diff --git a/frontend/src/index.css b/frontend/src/index.css
index e2ff451..06cb1b7 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -164,20 +164,13 @@
   }
 }
 
-/* Weekend column tint */
-/* Month view: paint the fc-daygrid-day-frame (FC6 inner div) with 5% white overlay.
-   The parent <td> bg is hidden behind the frame painted by --fc-neutral-bg-color, so
-   the tint must target the frame itself, not the td. */
-.fc .fc-day-sat .fc-daygrid-day-frame,
-.fc .fc-day-sun .fc-daygrid-day-frame {
-  background-color: hsl(0 0% 9% / 0.65) !important;
-}
-
-
-/* Weekend tint: timegrid column cells (week/day view) */
-.fc .fc-timegrid-col.fc-day-sat,
-.fc .fc-timegrid-col.fc-day-sun {
-  background-color: hsl(0 0% 5.5%) !important;
+/* Weekend columns: neutralise FullCalendar's built-in weekend td background.
+   The frame inherits --fc-neutral-bg-color identically to weekdays.
+   Weekend tint removed after 10+ attempts — cross-browser compositing divergence
+   (Firefox produces teal artifact from semi-transparent HSL on near-black bg). */
+.fc .fc-day-sat,
+.fc .fc-day-sun {
+  background-color: transparent !important;
 }